No real dispute there, however, if you look at Germany of the period, there was an almost equal chance that it could go fascist, or that it could go communist. Ernst Thälmann, the chairman of the KPD, was in Stalin’s pocket, and was just as megalomaniac as was Hitler.
He would likely not have started World War II, but the end result could have been a communist Europe aligned with the Soviet Union, dominating the world militarily and murdering far more people than Hitler did.